All well and good: if it makes you feel better, do it. Personally, I've never had a foot slip, never felt like that 1/4" of foam under my heel was putting me 'out of position' or the shoe failing to flex with my movements. Truth be known, when I'm squatting 450 or yankin' a dead weight off the floor, my mind is on my spinal alignment and the weight. If I'm thinkin' of anything else, it's the completion of the rep.
Still, ya gotta love the stylish nature of those All Stars!